1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3
 4namespace Rivet {
 5  using std::istream;
 6  using std::ostream;
 7
 8  // Example analysis to show how to use options in an analysis
 9  // Example of a custom class to be read in from an option.
10  class A {
11  public:
12    A() : a(-1.0) {}
13  private:
14    double a;
15    // Custom class must be streamable.
16    friend istream& operator>> (istream& is, A& a);
17    friend ostream& operator<< (ostream& os, const A& a);
18  };
19
20  // Custom class must be streamable.
21  istream& operator>> (istream& is, A& a) {
22    is >> a.a;
23    return is;
24  }
25  ostream& operator<< (ostream& os, const A& a) {
26    os << a.a;
27    return os;
28  }
29
30  class MC_OPTIONS : public Analysis {
31  public:
32
33    /// Constructor
34    RIVET_DEFAULT_ANALYSIS_CTOR(MC_OPTIONS);
35
36    /// @name Analysis methods
37    /// @{
38
39    /// Book histograms and initialise projections before the run
40    void init() {
41
42
43      // Parameters read in.
44      // A double.
45      double f = getOption<double>("foo", 1.0);
46      // A string.
47      string s = getOption<string>("bar", "");
48      // A custom object.
49      A a = getOption<A>("baz", A());
50
51      cout << "foo = " << f << endl;
52      cout << "bar = " << s << endl;
53      cout << "baz = " << a << endl;
54      value = f;
55      book(h, "hist",10,0,10);
56    }
57
58    // Perform the per-event analysis
59    void analyze(const Event&) {
60      h->fill(value);
61
62    }
63
64
65    /// Finalize
66    void finalize() {
67
68    }
69
70    /// @}
71
72
73  private:
74
75    /// @name Histograms
76    /// @{
77    Histo1DPtr h;
78    /// @}
79    double value;
80
81  };
82
83
84  RIVET_DECLARE_PLUGIN(MC_OPTIONS);
85
86}